• mommykink@lemmy.world
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    1 year ago

    For example we also say it’s 20 degrees celsius outside. And that’s not the proper SI unit either

    Can you elaborate on this? As an American without much experience with the SI system, I wouldn’t think twice if someone said this to me

    • rufus@discuss.tchncs.de
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      1 year ago

      What would you like to know? Regarding temperatures: ‘Kelvin’ is the proper SI unit. It starts with 0 at absolute zero. And then uses the same size for units as celsius uses. So 0°C (the point at which ice made from water melts) is 273.15 Kelvin. 20°C about where you’d wear a t-shirt is about 293 K. So we don’t say it that way but keep saying it’s 15 or 30°C outside.

      Scientists do it right. When you’re melting metal or talking about the temperature of the sun, you won’t have small numbers anyways and you won’t benefit from using celsius. That way you’ll have the 0 at the true 0 and aren’t arbitrarily using water at earth’s atmospheric pressure as your basis. You can translate it easily, anyways. Just add and substract the 273.15. You don’t need a formula and a calculator like when you translate between fahrenheit and celsius.

      • force@lemmy.world
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        11 months ago

        Actually since 2019 the Celsius is defined directly based off of the Kelvin by the SI